[PATCH V2] drm/exynos: Add fallback option to get non physically continous memory for fb

[Vikas Sajjan <vikas.sajjan@linaro.org>]

While trying to get boot-logo up on exynos5420 SMDK which has eDP panel
connected with resolution 2560x1600, following error occured even with
IOMMU enabled:
[0.880000] [drm:lowlevel_buffer_allocate] *ERROR* failed to allocate buffer.
[0.890000] [drm] Initialized exynos 1.0.0 20110530 on minor 0

To address the case where physically continous memory MAY NOT be a
mandatory requirement for fb, the patch adds a feature to get non physically
continous memory for fb if IOMMU is supported and if CONTIG memory allocation
fails.

Signed-off-by: Vikas Sajjan <vikas.sajjan@linaro.org>
Signed-off-by: Arun Kumar <arun.kk@samsung.com>
---
changes since v1:
	 - Modified to add the fallback patch if CONTIG alloc fails as suggested
	 by Rob Clark robdclark@gmail.com and Tomasz Figa <tomasz.figa@gmail.com>.

	 - changed the commit message.
---
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c |   19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index 8e60bd6..9a4b886 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -16,6 +16,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/exynos_drm.h>
 
 #include "exynos_drm_drv.h"
 #include "exynos_drm_fb.h"
@@ -165,11 +166,21 @@ static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
 
 	size = mode_cmd.pitches[0] * mode_cmd.height;
 
-	/* 0 means to allocate physically continuous memory */
-	exynos_gem_obj = exynos_drm_gem_create(dev, 0, size);
+	exynos_gem_obj = exynos_drm_gem_create(dev, EXYNOS_BO_CONTIG, size);
 	if (IS_ERR(exynos_gem_obj)) {
-		ret = PTR_ERR(exynos_gem_obj);
-		goto err_release_framebuffer;
+		/*
+		 * If IOMMU is supported then try to get buffer from
+		 * non-continous memory area
+		 */
+		if (is_drm_iommu_supported(dev))
+			exynos_gem_obj = exynos_drm_gem_create(dev,
+						EXYNOS_BO_NONCONTIG, size);
+		if (IS_ERR(exynos_gem_obj)) {
+			ret = PTR_ERR(exynos_gem_obj);
+			goto err_release_framebuffer;
+		}
+		dev_warn(&pdev->dev, "exynos_gem_obj for FB is allocated with\n"
+				"non physically continuous memory\n");
 	}
 
 	exynos_fbdev->exynos_gem_obj = exynos_gem_obj;
-- 
1.7.9.5